Shelf



FIG. 1 is a front perspective view of a shelf, showing my new design;

FIG. 2 is a top plan view of the invention illustrated in FIG. 1;

FIG. 3 is a left elevation view of the invention illustrated in FIG. 1;

FIG. 4 is a right elevation view of the invention illustrated in FIG. 1;

FIG. 5 is a front elevation view of the invention illustrated in FIG. 1;

FIG. 6 is a bottom plan view of the invention illustrated in FIG. 1; and,

FIG. 7 is a rear elevation view of the invention illustrated in FIG. 1. 

The ornamental design for a shelf, as shown and described. 